Controlling the Normal:ISO Aldehyde Ratio in a Mixed Ligand Hydroformylation Process

A method of controlling a multi-reaction zone, hydroformylation process for producing normal (N) and iso (I) aldehydes at a N:I ratio, the process comprising contacting an olefinically unsaturated compound with carbon monoxide, hydrogen and a catalyst comprising (A) a transition metal, (B) an organopolyphosphite ligand (obpl), and (C) an organomonophosphite ligand, the contacting conducted in first and one or more subsequent reaction zones and at hydroformylation conditions comprising a metal concentration and a obpl:metal ratio in each zone, the process further comprising a product separation zone from which catalyst is recovered and recycled, the method comprising changing the transition metal concentration in the first reaction zone by one or more of the following methods:

• 1. Partitioning the catalyst recycle from the product separation zone between the first reaction zone and one or more subsequent reaction zones;
• or
• 2. Decreasing the obpl:metal ratio by adding transition metal without any organobisphosphite ligand either as a transition metal precursor or a metal-organomonophosphite compound;
• or
• 3. Decreasing the transition metal concentration in the first reaction zone by removing up to 20% of the transition metal catalyst from the reaction system into a separate vessel;
• or
• 4. Returning transition metal catalyst removed in option (C) to the first reaction zone.